[PATCH v3 1/5] KVM: arm64: nv: Don't advertise FEAT_LPA2 for guest stage-1

[Oliver Upton <oupton@kernel.org>]

From: Wei-Lin Chang <weilin.chang@arm.com>

There is no FEAT_LPA2 support for NV guests as of now, but we missed
limiting it for the non-stage-2 granule size fields (TGRAN4, TGRAN16) in
ID_AA64MMFR0_EL1. Add the sanitisation.

Fixes: 9f75b6d447d7 ("KVM: arm64: nv: Filter out unsupported features from ID regs")
Signed-off-by: Wei-Lin Chang <weilin.chang@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
---
 arch/arm64/kvm/nested.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 4d83281a7a28..cd0dabcf3f81 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1875,6 +1875,17 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 		/* Hide CNTPOFF if present */
 		val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64MMFR0_EL1, ECV, IMP);
 
+		/* NV does not support FEAT_LPA2. */
+		if (SYS_FIELD_GET(ID_AA64MMFR0_EL1, TGRAN4, val) == ID_AA64MMFR0_EL1_TGRAN4_52_BIT) {
+			val &= ~ID_AA64MMFR0_EL1_TGRAN4;
+			val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN4, IMP);
+		}
+
+		if (SYS_FIELD_GET(ID_AA64MMFR0_EL1, TGRAN16, val) == ID_AA64MMFR0_EL1_TGRAN16_52_BIT) {
+			val &= ~ID_AA64MMFR0_EL1_TGRAN16;
+			val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN16, IMP);
+		}
+
 		/* Disallow unsupported S2 page sizes */
 		switch (PAGE_SIZE) {
 		case SZ_64K:
-- 
2.47.3